17640989 has 2 divisors, whose sum is σ = 17640990. Its totient is φ = 17640988.

The previous prime is 17640979. The next prime is 17641003. The reversal of 17640989 is 98904671.

17640989 is nontrivially palindromic in base 12.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17347225 + 293764 = 4165^2 + 542^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17640989 is a prime.

It is a super-2 number, since 2×17640989² = 622408985796242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17640919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8820494 + 8820495.

It is an arithmetic number, because the mean of its divisors is an integer number (8820495).

Almost surely, 2^17640989 is an apocalyptic number.

It is an amenable number.

17640989 is a deficient number, since it is larger than the sum of its proper divisors (1).

17640989 is an equidigital number, since it uses as much as digits as its factorization.

17640989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 17640989 is about 4200.1177364450. The cubic root of 17640989 is about 260.3200644135.

The spelling of 17640989 in words is "seventeen million, six hundred forty thousand, nine hundred eighty-nine".